Since mechanical external forces such as charging and cleaning are applied to the surface of an electrophotographic photosensitive member, the surface is demanded to have durability (for example, wear resistance) to such external forces,
As a technique in response to the demand, a technique has been conventionally known in which a resin (for example, curable resin) high in wear resistance is used on the surface layer of an electrophotographic photosensitive member.
On the other hand, the problem caused by an increase in wear resistance of the surface of an electrophotographic photosensitive member includes a reduction in cleanability due to a high coefficient of dynamic friction of the surface of an electrophotographic photosensitive member and a high rotary torque of the surface of an electrophotographic photosensitive member.
As a technique in response to the problem, PTL 1 describes a technique for providing a plurality of dimple-shaped concave portions on the surface (periphery) of an electrophotographic photosensitive member. Moreover, PTL 2 describes a technique for providing 76 or more and 1000 or less per 100 μm square of concave portions having an average long axis diameter of more than 3.0 μm and 14.0 μm or less on the surface of an electrophotographic photosensitive member.
In addition, PTL 3 describes an electrophotographic photosensitive member in which, when the surface roughness is expressed by RzJIS, the number of convex portions having a height of ½×RzJIS or more on the surface of the electrophotographic photosensitive member is 30 or more and 300 or less per 12 mm in measurement length, and describes an enhancement in cleaning performance resulting therefrom.